字符游戏——智能蛇

顾名思义，智能蛇是一条可以自己思考、判断并作出决定的蛇。

首先看看智能蛇的程序框架：
输出字符矩阵
WHILE not 游戏结束 DO
wait(time)
ch＝whereGoNext(Hx,Hy,Fx,Fy)
CASE ch DO
‘A’:左前进一步，break
‘D’:右前进一步，break
‘W’:上前进一步，break
‘S’:下前进一步，break
END CASE
输出字符矩阵
END WHILE
输出 Game Over!!!

接着是决定蛇行走的方向函数的伪代码：
// Hx,Hy: 头的位置
// Fx,Fy：食物的位置
function whereGoNext(Hx,Hy,Fx,Fy) {
// 用数组movable[3]={“a”,”d”,”w”,”s”} 记录可走的方向
// 用数组distance[3]={0,0,0,0} 记录离食物的距离
// 分别计算蛇头周边四个位置到食物的距离。H头的位置，F食物位置
// 例如：假设输入”a” 则distance[0] = |Fx – (Hx-1)| + |Fy – Hy|
// 如果 Hx-1，Hy 位置不是Blank，则 distance[0] = 9999
// 选择distance中存最小距离的下标p，注意最小距离不能是9999
// 返回 movable[p]
}

C语言实现

#include<stdio.h>
 #include<stdlib.h>
 #include<time.h>
 #include<conio.h>
 #include<windows.h>
 #define SNAKE_MAX_LENGTH 100
 #define SNAKE_HEAD 'H'
 #define SNAKE_BODY 'X'
 #define BLANK_CELL ' '
 #define SNAKE_FOOD '$'
 #define WALL_CELL '*'

char map[12][13] = {
    "************",
    "*H         *",
    "*          *",
    "*          *",
    "*          *",
    "*          *",
    "*          *",
    "*          *",
    "*          *",
    "*          *",
    "*          *",
    "************",
};

int snakeHeadX = 1, snakeHeadY = 1;
int snakeBodyX[SNAKE_MAX_LENGTH] = { 0 }, snakeBodyY[SNAKE_MAX_LENGTH] = { 0 };
int snakeBodyLen = 1;
int FoodX = 0, FoodY = 0;
int gameRunning = 1;
void gameover(void)
{
gameRunning = 0;
printf(“Game Over!”);
}
void putFood(void)
{
srand(time(NULL));
FoodX = rand() % 10 + 1;
FoodY = rand() % 10 + 1;
while (map[FoodX][FoodY] != BLANK_CELL)
{
FoodX = rand() % 10 + 1;
FoodY = rand() % 10 + 1;
}
map[FoodX][FoodY] = SNAKE_FOOD;
}
char move(int Hx,int Hy,int Fx, int Fy)
{
char movable[4] = { ‘w’,’a’,’s’,’d’ };
int distance[4] = { 0 };
int i, min = 0;
if (map[Hx-1][Hy] != WALL_CELL&&map[Hx-1][Hy] != SNAKE_BODY)
distance[0] = abs(Fx - (Hx-1)) + abs(Fy - Hy);
else
distance[0] = 9999;
if (map[Hx][Hy-1]!=WALL_CELL&&map[Hx][Hy-1] != SNAKE_BODY)
distance[1] = abs(Fx - Hx) + abs(Fy - (Hy-1));
else
distance[1] = 9999;
if (map[Hx+1][Hy]!=WALL_CELL&&map[Hx+1][Hy] != SNAKE_BODY)
distance[2] = abs(Fx - (Hx+1)) + abs(Fy - Hy);
else
distance[2] = 9999;
if (map[Hx][Hy+1] !=WALL_CELL&&map[Hx][Hy+1] != SNAKE_BODY)
distance[3] = abs(Fx - Hx) + abs(Fy - (Hy+1));
else
distance[3] = 9999;
for (i = 0; i < 4; i++)
if (distance[i] < distance[min]&&distance[i]!=9999)
min = i;
return movable[min];
}
void snakeMove()
{
char control = move(snakeHeadX, snakeHeadY, FoodX, FoodY);
int preSnakeHeadX = snakeHeadX;
int preSnakeHeadY = snakeHeadY;
switch (control)
{
case ‘w’:
snakeHeadX–;
break;
case ‘a’:
snakeHeadY–;
break;
case ‘s’:
snakeHeadX++;
break;
case ‘d’:
snakeHeadY++;
break;
default:
break;
}
if (map[snakeHeadX][snakeHeadY] == WALL_CELL || map[snakeHeadX][snakeHeadY] == SNAKE_BODY)
gameover();
map[snakeHeadX][snakeHeadY] = SNAKE_HEAD;
map[preSnakeHeadX][preSnakeHeadY] = BLANK_CELL;
if (snakeHeadX == FoodX && snakeHeadY == FoodY)
{
snakeBodyX[snakeBodyLen] = preSnakeHeadX;
snakeBodyY[snakeBodyLen] = preSnakeHeadY;
snakeBodyLen++;
map[preSnakeHeadX][preSnakeHeadY] = SNAKE_BODY;
putFood();
return;
}
if (snakeBodyLen <= 0)
return;
int i;
for (i = 0; i < snakeBodyLen - 1; i++)
{
snakeBodyX[i] = snakeBodyX[i + 1];
snakeBodyY[i] = snakeBodyY[i + 1];
}
snakeBodyX[snakeBodyLen - 1] = preSnakeHeadX;
snakeBodyY[snakeBodyLen - 1] = preSnakeHeadY;
int j;
for (j = 0; j < snakeBodyLen; j++)
map[snakeBodyX[j]][snakeBodyY[j]] = SNAKE_BODY;
map[snakeBodyX[0]][snakeBodyY[0]] = BLANK_CELL;
}
void printMap(void)
{
system(“cls”);
int i = 0;
for (i = 0; i < 12; i++)
printf(“%s\n”, map[i]);
}
int main()
{
putFood();
printMap();
while (gameRunning)
{
snakeMove();
printMap();
Sleep(100);
}
return 0;
}

虽称为智能蛇，但还是不够“智能”，经常会出现自己走死的情况